Endocrinology Practice Questions

Correct Answer: B

Rationale: Excess prolactin causes gynaecomastia due to its stimulatory effect on breast tissue growth in males. Prolactin inhibits the release of testosterone, leading to an imbalance in sex hormones and breast tissue development. Acromegaly is caused by excess growth hormone, not prolactin. Early menopause is unrelated to prolactin levels. Anaemia is typically not associated with prolactin excess. Thus, gynaecomastia is the most appropriate outcome of excess prolactin.

Correct Answer: B

Rationale: The correct answer is B: Intranasal vasopressin may be helpful. In diabetes insipidus, there is a deficiency of vasopressin leading to excessive urination and thirst. Administering vasopressin intranasally can help replace the deficient hormone, reducing urine output and thirst. Hypernatremia (choice A) can occur due to excessive water loss, but it is not always present. There is no osmolar gap (choice C) in diabetes insipidus. Urine specific gravity (choice D) is typically low in diabetes insipidus due to the dilute urine produced.

Correct Answer: C

Rationale: The correct answer is C: Bi-temporal hemianopia. Pituitary adenoma compressing the optic chiasm typically leads to bi-temporal hemianopia due to compression of the crossing fibers from the nasal visual fields. This results in loss of peripheral vision in both temporal visual fields. A: Bilateral inferior visual field deficits and B: Bilateral superior visual field deficits are less likely as they are not typical patterns associated with optic chiasm compression. D: Right homonymous hemianopia is incorrect as it is not associated with compression of the optic chiasm by a pituitary adenoma.

Correct Answer: B

Rationale: Thyroid acropathy, also known as thyroid dermopathy, is a skin condition commonly associated with Graves' disease. This autoimmune disorder causes an overactive thyroid gland, leading to high levels of thyroid hormones in the blood. The excess thyroid hormones can trigger changes in the skin, resulting in thyroid acropathy. Subclinical hypothyroidism (choice A) is characterized by slightly elevated TSH levels with normal thyroid hormone levels, not typically associated with thyroid acropathy. Myxoedema (choice C) refers to severe hypothyroidism and is not linked to thyroid acropathy. Medullary carcinoma of the thyroid (choice D) is a type of thyroid cancer and is not known to cause thyroid acropathy. Therefore, the correct answer is B, Graves' disease, as it is the most common condition associated with thyroid acropathy.

Correct Answer: C

Rationale: The correct answer is C: SIADH. Secondary hyperaldosteronism is characterized by increased aldosterone production due to factors outside of the adrenal glands, such as increased renin-angiotensin-aldosterone system activation. SIADH does not involve aldosterone, but rather involves inappropriate secretion of antidiuretic hormone leading to hyponatremia. In contrast, congestive cardiac failure, nephrotic syndrome, and cirrhosis of the liver can all lead to secondary hyperaldosteronism due to mechanisms such as decreased effective circulating volume, renal hypoperfusion, and increased angiotensin II levels, respectively.